U.S. patent number 5,308,333 [Application Number 08/066,916] was granted by the patent office on 1994-05-03 for air eliminating intravenous infusion pump set.
This patent grant is currently assigned to Baxter International Inc.. Invention is credited to James G. Skakoon.
United States Patent |
5,308,333 |
Skakoon |
May 3, 1994 |
**Please see images for:
( Certificate of Correction ) ** |
Air eliminating intravenous infusion pump set
Abstract
An intravenous set includes a spike or luer connector for
receiving pharmaceutical product solution, a pumping section, an
air eliminating filter, an anti-siphon valve and a connector for an
IV access device. The air eliminating filter includes an in-line
hydrophilic membrane and a hydrophobic membrane upstream thereof to
vent trapped gases to the atmosphere. The anti-siphon valve has a
positive crack pressure and is located downstream of the air
eliminating filter.
Inventors: |
Skakoon; James G. (Melrose,
MA) |
Assignee: |
Baxter International Inc.
(Deerfield, IL)
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Family
ID: |
25189936 |
Appl.
No.: |
08/066,916 |
Filed: |
May 24, 1993 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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804823 |
Dec 6, 1991 |
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Current U.S.
Class: |
604/110;
604/218 |
Current CPC
Class: |
A61M
5/36 (20130101); A61M 5/142 (20130101); A61M
5/14228 (20130101); A61M 39/24 (20130101); A61M
5/38 (20130101) |
Current International
Class: |
A61M
5/36 (20060101); A61M 39/00 (20060101); A61M
39/24 (20060101); A61M 5/142 (20060101); A61M
001/00 (); A61M 005/00 () |
Field of
Search: |
;604/122,123,126,251,247,252,256,81,82 ;128/DIG.12 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Yasko; John D.
Assistant Examiner: Cermak; Adam J.
Attorney, Agent or Firm: Kane, Dalsimer, Sullivan, Kurucz,
Levy, Eisele & Richard
Parent Case Text
This is a continuation of copending application Ser. No. 07/804,823
filed on Dec. 6, 1991, now abandoned.
Claims
What is claimed is:
1. An intravenous set having an upstream end and a downstream end
and comprising:
receiving means for receiving a supply of pharmaceutical product
solution at the upstream end;
peristaltic pumping section means in fluid communication with said
receiving means, said peristaltic pumping section means being
arranged and constructed to interface with a peristaltic pump;
an air eliminating filter in fluid communication with said pumping
section means for receiving said solution propelled by said
peristaltic pump form said receiving means;
a positive crack pressure anti-siphon valve downstream from said
air eliminating filter, wherein said valve is arranged to maintain
said solution within said eliminating filter at a preselected
threshold level above atmospheric pressure, wherein said valve
precludes flow of solution through sad valve in the direction of
said means for receiving a supply of pharmaceutical product
solution and wherein said valve seals to prevent flow of solution
through said valve away from said means for receiving a supply of
pharmaceutical product solution when pressure across said valve as
measured from said air eliminating filter to atmosphere falls below
a predetermined positive threshold; and
means for engaging an IV access device downstream from said valve
at the downstream end.
2. The intravenous set of claim 1 wherein said means for receiving
pharmaceutical product solution includes a spike with a lumen
therethrough.
3. The intravenous set of claim 1 wherein the means for receiving
pharmaceutical product solution includes a first LUER connector
means.
4. The intravenous set of any of claims 1, 2 or 3 wherein said air
eliminating filter includes a first membrane which allows the
passage of liquid therethrough but which precludes the passage of
gas therethrough and a second membrane which allows the passage of
gas to vent to the atmosphere but which precludes the passage of
liquids therethrough.
5. The intravenous set of claim 4 wherein said first membrane is a
hydrophilic membrane and wherein said second membrane is a
hydrophobic membrane.
6. The intravenous set of claim 4 wherein said pumping section
means and said air eliminating filter are in fluid communication
via a second Luer connector.
7. The intravenous set of claim 4 wherein said means for engaging
an IV access device includes a further Luer connector.
8. An intravenous set having an upstream end and a downstream end
and including:
receiving means for receiving a supply of pharmaceutical product
solution at the upstream end;
peristaltic pumping section means in fluid communication with said
receiving means for receiving a supply of pharmaceutical product
solution;
an air elimination filter in fluid communication with said pumping
section means for receiving said solution propelled by said
peristaltic pump from said receiving means;
a positive crack pressure anti-siphon valve downstream from said
air eliminating filter wherein said valve is arranged to maintain
said solution in said air elimination filter at a preselected
threshold level above atmospheric pressure;
wherein said valve seals to prevent flow of solution through said
valve when pressure across said valve as measured from said air
eliminating filter to atmosphere falls below a predetermined
positive threshold; and
means for engaging an IV access device downstream from said valve
at the downstream end.
9. The intravenous set of claim 8 wherein said positive crack
pressure valve includes means that prevent free flow of solution
into a patient.
10. The intravenous set of claim wherein said valve precludes flow
of solution through said valve in the direction of said means for
receiving a supply of pharmaceutical product solution.
11. The intravenous set of claim 8 wherein said valve has a crack
pressure of between 1.5 and 3.5 psi.
Description
BACKGROUND OF THE INVENTION
2. Field of the Invention
This invention relates to an intravenous infusion pump set
including an air eliminating filter with an in-line hydrophilic
membrane to trap air in a medical infusion device line and a
hydrophobic membrane to vent the trapped air. An anti-siphon valve
with a positive crack pressure is situated in the line between the
air eliminating filter and the infusion site.
2. Description of the Prior Art
The use of air eliminating filters in intravenous infusion pump
sets is often required with the use of large volume pharmaceutical
product bags due to the difficulty of purging all the air from the
system. Furthermore, high infusion rate systems have an increased
severity upon air embolism and therefore particularly require
effective air elimination.
Air eliminating filters come in two different designs. The first
design uses a standard hydrophilic membrane to prevent the passage
of air bubbles and other gases through the apparatus. The pore size
of a hydrophilic membrane is typically 0.2 micrometers. Hydrophilic
membranes, when wetted, prevent the passage of air and gases
therethrough up to the bubble point pressure but allow the passage
of liquids therethrough. An intravenous set with an in-line
hydrophilic membrane therefore allows a user to purge air from the
intravenous set until liquid wets the filter and then no air will
pass. The filter then collects air or gases on the upstream side of
the membrane. Therefore, air accumulates during operation of the
first design of filter thereby restricting flow of the liquid as
air accumulates. The restriction increases until the flow stops
when the membrane is covered by air thereby causing a complete
occlusion.
The second design of filter used for air elimination includes an
in-line hydrophilic membrane similar to the first design and
additionally includes a vent covered with a hydrophobic membrane on
the upstream side of the hydrophilic membrane housing thereby
allowing the escape of the trapped gases. The hydrophobic membrane
will allow only air (or gases) to pass therethrough thereby
removing the trapped air from the filter. Therefore, this second
design of filter will continue to pass the liquid from a liquid/air
bubble mixture whereas the first design allows the bubbles to
accumulate and eventually occlude the passage of liquid.
The use of this second design of filter which includes an in-line
hydrophilic membrane and a hydrophobic membrane placed upstream of
the hydrophilic membrane is well-known in the prior art. An example
of such a filter is disclosed in U.S. Pat. No. 3,650,093 to
Rosenberg.
However, as such prior art apparatus heretofore uses no anti-siphon
or positive crack pressure valve means downstream of the filter,
two problems will occur. Firstly, under certain common combinations
of flow rate and resistance, lowering the infusion site relative to
the filter will produce a negative pressure in the set resulting in
air being admitted through the hydrophobic membrane. While this air
can never pass through the hydrophilic membrane, its entry results
in a bolus of pharmaceutical product to the patient. Secondly, if
air exists in the filter either by incomplete purging, by entry
from the pharmaceutical product container, or by prior admission
through the hydrophobic membrane, elevation of the infusion site
(such as may occur during ambulatory circumstances) will expel this
air through the hydrophobic membrane. Retrograde blood flow from
the patient will occur equal to the volume of air expelled.
An intravenous set which includes an air eliminating filter placed
between the pharmaceutical product bag and the pump is similarly
deficient. This location works well if the filter is always below
the fluid level in the reservoir, as is common practice. However,
if the pharmaceutical product bag of such a set is inadvertently or
otherwise placed below the pump, then the air eliminating filter
may draw air into itself and result in an error in flow rate or
total occlusion. The air will not pass the hydrophilic membrane,
but can cause air locking of the filter thereby preventing liquid
from being drawn from the pharmaceutical product reservoir.
An intravenous set which includes an air eliminating filter between
the pump and the patient is also deficient. If the patient is
placed below the filter of such a set, the filter may draw in air
from the atmosphere, particularly with low flow rates, thereby
causing an additional error in flow rate. Further, if the patient
is then moved from below the filter to above the filter, backflow
of fluid from the patient to the filter will occur causing the
intravenous set to fill with blood from the patient. Moreover, if
the patient is below the pharmaceutical product bag and the set is
not properly in the pump and therefore not occluded, a free flow,
or siphoning, of solution into the patient will occur.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide an
intravenous set which prevents retrograde blood flow, unintended
boluses of pharmaceutical product to the patient and air locking of
the set, particularly due to negative system pressures.
It is therefore a further object of this invention to provide an
intravenous set which includes an air eliminating filter and which
prevents the occurrence of negative system pressures, particularly
across the air eliminating filter.
It is therefore a still further object of this invention to provide
an intravenous set which prevents negative system pressures under
various combinations of flow rate, flow resistance and position of
the intravenous set with respect to the infusion site.
It is therefore a still further object of this invention to provide
an intravenous set which prevents free flow, or siphoning, of
pharmaceutical product into the patient.
This invention is an intravenous set with a means for receiving
pharmaceutical product, a pumping means, an air eliminating filter,
an anti-siphon valve with positive crack pressure and a connector
to attach to an intravenous access device. The air eliminating
filter includes an in-line hydrophilic membrane to prevent the
passage of air and gases therethrough and a hydrophobic membrane to
vent the trapped air to the atmosphere. The anti-siphon valve with
positive crack pressure is downstream of the air eliminating
filter. The anti-siphon valve allows no forward flow until the
crack pressure is exceeded. In other words, the valve prevents
either forward flow when the pressure differential falls below the
crack pressure or reverse flow. The use of the anti-siphon valve
prevents negative system pressures within the intravenous set and
any retrograde blood flow or unintended boluses associated
therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will become
apparent from the following description and claims, and from the
accompanying drawings, wherein:
FIG. 1 discloses a perspective view of the air eliminating infusion
pump set of the invention associated with an infusion pump shown in
phantom.
FIG. 2 is an enlarged fragmentary perspective view, partly in
section, of the air eliminating filter.
FIG. 3 is a cross sectional view of the filter along plane 2--2 of
FIG. 1.
FIG. 4 is a view similar to FIG. 1 disclosing an alternate
embodiment of air eliminating infusion pump set with a Luer
connector substituted for the spike.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail wherein like numerals
indicate like elements throughout the several views, intravenous
set 10 includes spike 12 for engaging a pharmaceutical product bag
(not shown). Spike 12 includes a pointed end 14 to enter the
puncture port (not shown) of the pharmaceutical product bag. Spike
12 further includes lumen 16 for communicating pharmaceutical
product therethrough to the pumping section 18 via tubing 20.
Spike 12 may be replaced with any means for engaging a source of
pharmaceutical product. A Luer connector 11 (see FIG. 4) is a
particularly frequent substitution for spike 12.
Pumping section 18, in conjunction with an infusion pump 19, shown
in phantom, propels the pharmaceutical product from spike 12
downstream to air eliminating filter 24 through tubing 22. Tubing
22 may include a luer connector set 23 to allow the interchangeable
engagement of various components of intravenous set 10. A typical
infusion pump 19 usable with the invention may include a linear
peristaltic mechanism.
As shown in FIGS. 2 and 3, air eliminating filter 24 includes a
body 26 having fluid input port 30 adapted to be coupled with
tubing 22. Input port 30 leads to internal chamber 32 which
includes hydrophobic membranes 34. Air and other gases trapped in
chamber 32 can pass through hydrophobic membranes 34 and passageway
37 to the atmosphere. Internal chamber 32 further includes
hydrophilic membrane 38 spaced parallel to hydrophobic membranes
34. Liquids pass through hydrophilic membrane 38 to exit port 44.
Exit port 44 is in fluid communication with anti-siphon valve 46
(see FIG. 1) which in turn is coupled with and in fluid
communication with tubing 48.
Anti-siphon valve 46 is a check valve with a positive crack
pressure. Valve 46 prevents reverse flow through tube set 10 (i.e.
from valve 46 to filter 24) and allows forward flow (i.e. from
filter 24 to valve 46) only when the pressure differential across
valve 46 is greater than the crack pressure of said valve 46.
Further, valve 46 reseals to prevent further forward flow whenever
the pressure across valve 46 falls below said positive crack
pressure. This arrangement precludes any retrograde fluid flow (e
g. blood) from occurring. Also, importantly, this arrangement
guarantees that the pressure within tube set 10 between pumping
section 18 and valve 46, and particularly within filter 24 is
always above atmospheric pressure by at least the crack pressure of
valve 46 thereby precluding admission of atmospheric air into
filter 24 through hydrophobic membrane 34.
The present invention contemplates a valve 46 with a crack pressure
of 1.5 to 3.5 psi. This is above the range of commonly encountered
head pressures and is thereby effective in preventing both
uncontrolled free flow, or siphoning, and admission of air into the
filter. A valve of this type is disclosed in U.S. Pat. No.
4,535,820.
Tubing 48 engages luer connector 50. Luer connector 50 is used to
adapt to an IV access device which engages the patient.
To use this intravenous set 10, the user employs commonly accepted
IV techniques.
Thus, the several aforementioned objects and advantages are most
effectively attained. Although a single preferred embodiment of the
invention has been disclosed and described in detail herein, it
should be understood that this invention is in no sense limited
thereby and its scope is to be determined by that of the appended
claims.
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